<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="./css/inputnumber.css" />
    <link rel="stylesheet" href="./css/index2.css" />
    <title>购物车</title>
  </head>
  <body>
    <div class="app-container" id="app">
      <!-- 顶部banner -->
      <div class="banner-box"><img src="./img/fruit.jpg" alt="" /></div>
      <!-- 面包屑 -->
      <div class="breadcrumb">
        <span>🏠</span>
        /
        <span>购物车</span>
      </div>
      <!-- 购物车主体 -->
      <div class="main" v-if="fruitList.length > 0">
        <div class="table">
          <!-- 头部 -->
          <div class="thead">
            <div class="tr">
              <div class="th">选中</div>
              <div class="th th-pic">图片</div>
              <div class="th">单价</div>
              <div class="th num-th">个数</div>
              <div class="th">小计</div>
              <div class="th">操作</div>
            </div>
          </div>
          <!-- 身体 -->
          <div class="tbody">
            <div class="tr" :class="{active : item.isChecked}" v-for="(item, index) in fruitList" :key="item.id">
              <div class="td"><input type="checkbox" v-model="item.isChecked" /></div>
              <div class="td"><img :src="item.icon" alt="" /></div>
              <div class="td">{{ item.price }}</div>
              <div class="td">
                <div class="my-input-number">
                  <button class="decrease" @click="decrease(item.id)" :disabled="item.num <= 1"> - </button>
                  <span class="my-input__inner">{{ item.num }}</span>
                  <button class="increase" @click="increase(item.id)"> + </button>
                </div>
              </div>
              <div class="td">{{ item.price * item.num }}</div>
              <div class="td"><button @click="remove(item.id)">删除</button></div>
            </div>
          </div>
        </div>
        <!-- 底部 -->
        <div class="bottom">
          <!-- 全选 -->
          <label class="check-all">
            <input type="checkbox" v-model="isAll"/>
            全选
          </label>
          <div class="right-box">
            <!-- 所有商品总价 -->
            <span class="price-box">总价&nbsp;&nbsp;:&nbsp;&nbsp;¥&nbsp;<span class="price">{{ count4Sum }}</span></span>
            <!-- 结算按钮 -->
            <button class="pay">结算( {{ count4Total }} )</button>
          </div>
        </div>
      </div>
      <!-- 空车 -->
      <div class="empty" v-else>🛒空空如也</div>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <script>
      // 默认水果列表
      const defaultArray = [
            {
                id: 1,
                icon: './img/火龙果.png',
                isChecked: true,
                num: 2,
                price: 6,
            },
            {
                id: 2,
                icon: './img/荔枝.png',
                isChecked: false,
                num: 7,
                price: 20,
            },
            {
                id: 3,
                icon: './img/榴莲.png',
                isChecked: false,
                num: 3,
                price: 40,
            },
            {
                id: 4,
                icon: './img/鸭梨.png',
                isChecked: true,
                num: 10,
                price: 3,
            },
            {
                id: 5,
                icon: './img/樱桃.png',
                isChecked: false,
                num: 20,
                price: 34,
            }
        ]
      const app = new Vue({
        el: '#app',
        data: {
          // 水果列表（从localStorage中获取，若获取不到，则使用默认水果列表）
          fruitList: JSON.parse(localStorage.getItem('list')) || defaultArray
        },
        computed: {
            isAll: {
                get() {
                    // 所有的小选择框都被选中，则全选框才被选中
                    return this.fruitList.every(item => item.isChecked)
                },
                // value是复选框的值
                set(value) {
                    this.fruitList.forEach(item => {
                        // 所有的小选择框都设置成为全选框的值
                        item.isChecked = value
                    });
                }
            },
            // 统计选中的合计值
            count4Sum() {
                // let sum = 0
                // this.fruitList.forEach(item => {
                //     if(item.isChecked){
                //         sum += item.num * item.price
                //     }
                // })
                // return sum
                return this.fruitList.reduce((sum, item) => {
                    if(item.isChecked){
                        sum += item.num * item.price
                        return sum
                    }else{
                        return sum
                    }
                }, 0)
            },
            // 统计选中的总数
            count4Total() {
                // let total = 0
                // this.fruitList.forEach(item => {
                //     if(item.isChecked){
                //         total += item.num 
                //     }
                // })
                // return total
                return this.fruitList.reduce((total, item) => {
                    if(item.isChecked){
                        total += item.num
                        return total
                    }else{
                        return total
                    }
                }, 0)
            }
        },
        watch: {
            fruitList: {
                deep: true,
                handler(newValue) {
                    // 需要将变化后的数据存入localStorage中（转JSON)
                    localStorage.setItem('list', JSON.stringify(newValue))
                }
            }
        },
        methods:{
            remove(id) {
                this.fruitList = this.fruitList.filter(item => item.id !== id)
            },
            decrease(id) {
                const fruit = this.fruitList.find(item => item.id === id)
                fruit.num--
            },
            increase(id) {
                const fruit = this.fruitList.find(item => item.id === id)
                fruit.num++
            }
        }
      })
    </script>
  </body>
</html>
